How to retrieve short-term credentials for CLI use with AWS Single Sign-on

Today, AWS made it easier to use the AWS Command Line Interface (CLI) to manage services in your AWS accounts. Now you can sign into the AWS Single Sign-On (AWS SSO) user portal using your existing corporate credentials, choose an AWS account and a specific permission set, and get temporary credentials to manage your AWS services through the AWS CLI.

Previously, when you issued commands from the CLI to access resources in each of several AWS accounts, you had to remember the password for each account, sign in to each AWS account individually, and fetch the credentials for each account one at a time. Now, AWS SSO eliminates the need to sign in to each AWS account individually to get temporary credentials. Instead, you can sign in to the AWS SSO user portal once using your existing corporate credentials and then fetch temporary credentials for any of your authorized AWS accounts to use with the AWS CLI to access the resources in that account, limited by the permissions granted to you.

In this blog post, I’ll show how to fetch temporary credentials from the AWS SSO user portal to use with the AWS CLI to access resources in your AWS accounts. First, I’ll show you how to obtain short-term credentials for any account for a permission set for which you are authorized. Next, I’ll show you three ways to use these credentials.

For this scenario, let’s say I am an administrator at “AnyCompany” and I want to list instances in two AWS accounts by using the AWS CLI command, aws ec2 describe-instances. “AnyCompany” has enabled access to AWS accounts through AWS SSO.

Prerequisites

You need to install the AWS CLI to use this feature. You also need to configure AWS SSO, connect a corporate directory, and grant access to users or groups to access AWS accounts with permission sets. To learn more, see, “Introducing AWS Single Sign-On“.

How to access resources in your AWS accounts by using AWS SSO and the AWS CLI

1. Sign in to the AWS SSO user portal using your corporate credentials. If you don’t know the URL of your AWS SSO user portal, ask your IT administrator. This URL can be found in AWS SSO Console in the Dashboard menu, under “User portal URL” section. In the user portal, you will see the AWS accounts to which you have been granted access.

2. Choose “AWS Account” to expand the list of AWS accounts.

3. Choose the AWS account that you want to access using the AWS CLI. This expands the list of permission sets in the account that you can use to access the account. For this example, I choose “Administrator” permission set which has the necessary permissions to create security groups in accounts. I then choose “Command Line” or “Programmatic Access” associated with the “Administrator” permissions set.

4. AWS SSO shows the credentials you requested in the appropriate format for your operating system. If you need credentials for an operating system that is different from the one shown, you can switch between the MacOSand Linux and Windows tabs. AWS SSO offers three options to use the temporary security credentials (these credentials are valid for up to 60 minutes; see the following screenshot for examples of each option):

a. To run commands from the AWS CLI against the selected AWS account, copy the commands in the “Setup AWS CLI environment variables” section and paste the commands in the terminal window to set the necessary environment variables. These environment variables will be effective in the current terminal window.

b. To run commands from multiple terminal windows against the same AWS account, copy the profile in the “Setup AWS CLI profile” sectionto setup a new named profile in your AWS credentials file. To learn more, see: “Configuration and Credential Files“. You then will be able to use the –profile option with your AWS CLI command to use this credential. This will be effective in all terminal windows that use the same credential file.

c. To access AWS resources from an AWS service client, use the credentials under the “Copy individual values” section to initialize your client. For more information, see the “Use the temporary credentials to access AWS resources” section on “Getting Temporary Credentials with AWS STS“.

5. Move your mouse over the option you want to copy credentials. I chose option 1.

6. I have copied, pasted, and run the AWS CLI environment variables commands in my terminal window:

7. Optionally, you can verify that the credentials are set up correctly by running the “aws configure list” command. Verify that the access_key and secret_key have values assigned.

8. Now you can run any applicable AWS CLI commands (based on the permission set granted to you by your administrator). In the following example, I list instances in my AWS account.

9. To run the same (or different) AWS CLI command against a different AWS account, repeat this process, starting with Step 3. By keeping the AWS SSO user portal open in a browser window, you can easily switch to another AWS account without needing to sign in again. Every time you want to switch between accounts/permission sets or do additional work in an account after the temporary credentials expire, just copy fresh credentials for that account/permission set from the user portal.

Conclusion

In this post, in order to manage services using the AWS CLI, I’ve showed you how to use your existing corporate username and password to get temporary credentials from AWS SSO. If you have questions, please start a new thread in the AWS SSO Forum.